Question

A fez, the cap used by the Turks, is shaped like the frustum of a cone. If its radius on the open side is 10 cm, radius at the upper base is
4 cm and its slant height is 15 cm, then find the area of material used for making it. `["Use"  π = 22/7.]`

Answer 1

We have, 

Radius of open side, R = 10 cm,

Radius of upper base, r = 4 cm and

slant height, l = 15 cm

Now,

The area of material used = π(R + r)l + πr²

`= 22/7xx(10+4)xx15+22/7xx4xx4`

`= 22/7xx14xx15+22/7xx4xx4`

`= 22/7xx(14xx15+4xx4)`

`= 22/77xx226`

`=4972/7  cm"`

≈ 710.28 cm²

So, the area of material used for making the fez is 710.28 cm².